New Concepts in para -Aramid Fibers 1

Copolyaramids were synthesized in N-methylpyrrolidone (NMP) and directly spun from isotropic solutions using wet or dry-wet spinning methods. Hot drawing was done at temperatures > 400°C. In most cases, three aromatic diamines were used to produce the copolyaramid. By selecting different chemical structures, it was possible to influence textile properties over a wide range. The initial modulus was >90 N/tex in some compositions. Tenacities of 200 cN/tex were realized. By incorporating kinked or flexible monomers, it was possible to obtain elongations up to 6%. Because of their chemical structure, these fibers exhibit remarkable stability against chemical or physical ageing. This technological concept, to use coaramids composed of various chemical structural elements, can produce specially tailored properties for individual end uses.